Apparatus for unseating milk can covers



Feb. 21, 1956 w, w s

APPARATUS FOR UNSEATING MILK CAN COVERS 3 Sheets-Sheet 1 Filed April 27,1953 IN V EN TOR. WESLEY VVISE Feb. 21, 1956 w, WISE APPARATUS FORUNSEATING MILK CAN COVERS 3 Sheets-Sheet 2 Filed April 27, 1955 KNOCKERFRAME A/R VALVE INVENTOR. WESLEY VVIJ'E' BY @MQQWAW ATTORNEKS Feb. 21,N56

W. WISE APPARATUS FOR UNSEATING MILK CAN COVER:

Filed April 27. 1953 3 Sheets-Sheet. 3

KNocKEk CYLINDER KNOCKER FRAME HIGH PRESSURE All? TRANSFORMER i mvoc/rskINVENTOR. WESLEY l/V/SE ATToR/vE-Ks United States Patent APPARATUS FORUNSEATING MILK CAN COVERS Wesley Wise, Kiel, Wis,

Application April 27, 1953, Serial No. 351,349

8 Claims. (Cl. 226129) This invention relates to an improved apparatusfor automatically unseating milk can covers from their respective cantops as the cans are advanced by a conveyor to their destination.

In the operation of .a creamery the raw milk is usually brought into thecreamery in conventional milk cans having their .open tops closed bysuitable covers. Milk cans utilize two diflerent and distinct types ofcovers, one commonly known as the umbrella type, and the other as a plugtype. These covers have a portion fitted into the cylindrical neck ofthe can top and are retained in sealing engagement therewith byfriction.

The present invention is directed to an apparatus for unseating milk cancovers of the type having their outer marginal edges projecting slightlybeyond the perimeter of their respective can tops, whereby theprojecting marginal edges of the can covers may be engaged by a knocker,or the like, for the purpose offreeing or unseating the covers fromtheir seats to facilitate the subsequent removal of the covers from thecans in the operation of emptying the filled cans into a suitablereceptacle or weigh can.

In the initial step of processing raw milk, the filled cans are usuallyplaced upon a suitable conveyor for transporting them from the unloadingdock or platform to a receiving room or station where the milk may bedumped into a conventional weigh can by an operator stationed adjacentthereto. Heretofore it has been customary to have an attendant stationedalongside the conveyor to manually unseat each cover so that when :thecans reach the operator at the weigh .can, he may, with-.outinterruption, remove the cover and dump the .con-

tents of each can into the weigh .can. By the employment of the presentinvention the services :of the attendant for manually unseating thecancovers may be dispensed with, as the present invention automatically.unseats each can cover and leaves it loosely disposed-on .top of thecan in a canted position whereby .the .operator at the weigh can mayreadily remove the loose covers .and dump the contents of the cans intothe weigh can.

An important object of the present invention, .therefore, is to providean apparatus for automatically .unseating the covers of milk .cans asthey are successively conveyed to a suitable receptacle or weighcan,without interrupting the traveling movement of the cans.

A further and more specific object of the invention is to provide, incombination with a suitable conveyor, an apparatus comprising a knockerhaving an operating mechanism which is controlled by movement of the.cans to automatically eifect actuation of the knocker and cause it toengageiand unseat each cover from their respective can tops, as the cansare successively conveyed through the apparatus to the weigh can.

A further object is to provide an apparatus for unseating milk cancovers from cans being conveyed by a suitable conveyor from one stationto another, which apparatus comprises a suitable supporting structuredisposed over the conveyor and having 'a membermounted ice for verticalsliding movement therein and provided at its lower end with inwardlyturned portions, which will hereinafter be termed knockers. Theseknockers are normally positioned beneath the path of travel of theopposed marginal edge portions of the milk can covers, when the coversare in their normal closed positions on their respective cans, and areautomatically actuated by a fluid-operated mechanism which is controlledby the movement of the cans, and whereby as each can passes theknockers, said fluid operated mechanism ,is .automatically actuated tocause the knockers to operate .and unseat the can covers.

A further and more specific object of the invention is to provide anapparatus for unseating milk can covers, comprising a conveyor having aknocker frame mounted for vertical sliding movement thereover, saidknocker frame being operatively connected to a fluid actuated mechanismcomprising a plurality-of electric control elements adapted to beactuated by the movements of the .cans and the knocker frame toautomatically control the operation of the knocker frame.

Other objects of the invention reside in the simple and inexpensiveconstruction of the apparatus; in the provision of such an apparatuswhich will unseat the can covers with a positive action, as the cans aresuccessively fed thereto; and in the provision of such an apparatuswherein the can cover engaging elements, when actuated, engage the coverwith a hammer-like action, thereby to completely unseat each coverregardless of its frictional engagement with the can neck.

These and other objects of the invention and the means :for theirattainment Will be more apparent from the following description taken inconnection with the accompanying drawings.

In the accompanying drawings there has been disclosed'astructuredesigned tocarry out the various objects of the invention, but it is tobe understood that the invention is not confined to the exact featuresshown, as various changes may be made within the scope of the claimswhich follow.

In the drawings:

Figure 1 is a longitudinal vertical sectional view on the line 11 ofFigure 2, showing the invention positioned over the path of travel ofthe milk cans;

Figure 2 is a sectional elevation on the line '22 of Figure 1, showingin full and dotted lines the two positions of the knockers withreference to the can'covers;

Figure 3 is a sectional plan view on the line 3-3 of Figure 2; and

Figure 4 -is a diagrammatic view illustrating the oper ating and controlmechanism for the knockers.

In the selected embodiment of the invention herein disclosed, there isillustrated in Figures 1, 2, and 3, for the purposes 'of disclosure, aportion of a conveyor, generally designated by the numeral 2, comprisinga .flexible conveying element 3, .which may be in the form of an endlesschain or belt supported upon suitable sprockets or pulleys, not shown inthe drawings. In the present instance, a single conveyor element 3isemployed, but it is to be understood that two or more may beimountedz-in parallel relation, .if deemed necessary. Longitudinallyextending bottom rails 44 are provided at .each side of the conveyorelement 3 adapted to be engaged by the can bottoms as will be understoodby reference to Figures 2 and 3. Guide rails 55 are also provided forretaining the containers or can 6 in position on the conveyor as will beunderstood.

,An important feature of the present invention relates in the novelmeans provided for unseating the cover 7 from .each can top, as the canstravel uninterruptedly from the unloading platform, not shown, to theirdesignation, such as the usual weigh can or bucket into which thecontents of the cans is dumped by an attendant stationed adjacentthereto.

To thus unseat the can covers, a supporting structure generallydesignated by the numeral 8, is provided over the conveyor 2 andcomprises upright frame members 9-9 having their lower ends suitablysecured to the guide rails 5-5 by such means as welding, rivets orbolts. The upper ends of the upright frame members 9--9 are securedtogether in spaced relation by a suitable cross member or header 11.

Slidably mounted within the supporting structure 8 is a rectangularknocker frame, generally designated by the number 12, comprising sidemembers 13-43 and a top member 14, which members may be formed from asingle bar of strap iron to facilitate construction. The side members1313 of the knocker frame are slidably supported in suitable guides 15secured to the inner faces of the upright frame members 99, as indicatedin Figure 2, whereby said guides cooperate to vertically guide theknocker frame in its up-and-down movements, as will subsequently bedescribed.

As best illustrated in Figure 2, the lower ends of the side members 1313of the knocker frame are bent inwardly at substantially right angles toprovide knocker elements 1616 adapted to engage the outer marginal edgeportions of each can cover with sufficient impact to unseat the coversas illustrated in dotted lines in Figure l, as the cans successivelypass the knocker.

Conventional milk cans utilize two types of covers, one known as theumbrella type and the other the plug type. Both types are retained inclosed positions in the can top by friction, and because of theirrelatively large diameter, sometimes require considerable force tounseat them. Heretofore an operator has been stationed alongside theconveyor for manually unseating-the covers, as the filled cans areconveyed toward the weighing can. In some instances, it has beenextremely difiicult for an attendant to thus manually unseat each coverwithout at times interrupting the travel of the cans, particularly ifsome of the covers have been slightly deformed so as to increase theirfrictional engagement with, their respective can tops.

The present invention eliminates the operation of thus manuallyunseating the covers and insures complete unseating of each can cover orclosure without interruption or failure. Of the two types of can coversabove referred to, the umbrella type is the most popular, and such acover is therefore illustrated in the accompanying drawings.

To insure positive unseating of each can cover, means is provided forimparting a hammer-like blow to each cover as the cans are conveyedtowards the weigh can or milk dumping station. Such means is showncomprising a pair of inturned knocker terminals 1616, provided at thelower end of the knockcr frame and adapted to engage the perimeter ofeach can cover at opposite sides with a hammer-like blow, thereby tounseat each cover, as illustrated in Figures 1 and 2. The knockerterminals may be integrally formed with the lower ends of the sidemembers 1313 of the knocker frame 12, as shown in Figure 4'. i

To thus actuate the knocker, a pneumatic cylinder 17 is shown mounted inthe supporting frame 8 by suitable cross members 18 and 19 having theirterminals secured to the upright frame members 99 by suitable means, notshown. A piston 21 is mounted within the cylinder 17 and has a rod 22projecting from the upper end of the cylinder which is operativelyconnected to the upper member 14 of the knocker frame 12, as illustratedin Figures 2 and 4.

To cause the knocker frame to impart a hammer-like blow to each cancover, means is provided for introducing a high pressure fluid into thelower end of the cylinder 17, below the piston 21, such as compressedair. To thus direct the flow of high pressure air to and from theopposed ends of the cylinder, an electrically operated valve device isshown mounted in the lower portion of the cylinder, and comprisesopposed solenoids 23 and 24 operatively connected to a slide valve 25mounted in a cylindrical valve chamber 26, as indicated in Figure 4. Aconduit 27 has one end in communication with the valve chamber 26 andhas its opposite end connected to a source of air under pressure.

A passage 28 establishes communication between the valve chamber 26 andthe lower end of the cylinder 17 below the piston 21, and a passage 29connects the valve chamber 26 with the upper end of the cylinder, asindicated at 31, in Figure 4. The lower ends of the passages 28 and 29are so spaced with respect to the length of the control valve 25 thatthe passages 28 and 29 are alternately opened and closed duringoperation of the apparatus, by energization of the solenoids 23 and 24by the control means, next to be described.

The control means is best illustrated in Figure 4, and comprises a pairof suitable control switches, generally designated by the numerals 32and 33, which are normally in circuit-opening positions, as indicated inFigure 4. Control switch 32 is suitably secured to one of the uprightframe members 9 of the supporting structure, and comprises a fixedcontact 34 and a movable contact 35. The movable contact 35 is adaptedto be moved into electrical contact with the fixed contact 34 byactuation of an arm 36 having an anti-friction roller 37 mounted at theouter end thereof normally positioned in the path of each can body,whereby as the cans successively pass the switch 32, said switch ismomentarily closed to effect energization of the solenoid 23.

Electric energy is supplied to the solenoids 23 and 24 from a suitabletransformer 38 having its primary connected to a suitable source ofelectric energy, not shown, by conductors 39 and 41. One side of thesecondary of the transformer has a wire 42 connecting it to a wire 43which is electrically connected to the fixed contacts of the controlswitches 32 and 33, as clearly illustrated in the wiring diagram, Figure4. The other side of the secondary has a wire 44 connecting it to a wire45 which is electrically connected to the windings of the solenoids 23and 24. A wire 46 connects the movable contact 35 of control switch 32to the winding of solenoid coil 23, thus providing a circuit therefor.

The upper control switch 33, like the lower control switch 34, comprisesa fixed contact 47 and a movable contact 48 which has an arm 49 carryingan anti-friction roller 51, normally positioned in the path of theknocker frame 12, whereby when said frame is moved upwardly by actuationof the piston 21, the control switch 33 is momentarily closed to effectenergization of the solenoid 24 through a wire 52.

In the operation of the novel apparatus herein disclosed, the cans aredelivered onto the conveyor 2 in spaced relation, as indicated in Figure1, and as each can passes through the supporting frame 8, it engages theroller 37 of the movable contact 35 of the lower control switch 32,whereupon contact 35 enggaes contact 34 and completes a circuit tosolenoid 23 through wires 42 and 43, contacts 34 and 35, wire 46 to oneend of the winding of solenoid 23, thence through a portion of wire 45and through wire 44 to the other side of the secondary of transformer38.

Such eneregization of solenoid 23 instantly shifts the slide valve 25 tothe position indicated in dotted lines in Figure 4, wherebycommunication is established between the lower end of cylinder 17 andthe high pressure conduit 27, through the passage 28 and valve chamber26, whereby the piston is suddenly forced upwardly and causes theknocker terminals 16 to impinge against the overhanging perimeter of thecan cover 7 with a hammer-like action, which positively unseats thecover and leaves it resting loosely upon the open top of the can, asillustrated at the lefthand end of Figure 1.

As the knocker frame is thus moved upwardly to unseat a can cover, theupper portion thereof engages the roller 51 of control switch 33,whereby a circuit is completed to solenoid 24 through wires 42 and 43,contacts 47 and 48, Wire 52 to one end of the winding of solenoid 24,thence through a portion of wire 45 and through wire 44 -to the otherside of the secondary of transformer 38. When the solenoid 24 is thusenergized, the slide valve 25 is shifted to the opposite end of thevalve chamber 26 and thereby establishes communication between =the airsupply conduit 27 and the upper end of the cylinder through the passage29, thereby effecting a positive return movement of the knocker frame toits normal position. It is to be understood that the lower controlswitch 32 is opened while the knocker frame is in its upper position sothat the solenoid 23 is deenergized to permit the solenoid 24 to actuatethe slide valve 25.

The pneumatically operated control device herein disclosed, includingcylinder 17, piston 21 and solenoids 23 and 24. is well known in theart, and is readily available upon the market, and it is thereforebelieved unnecessary to herein further describe the same in detail.

To afford a clearer understanding of the operation of this particularpneumatic control device, it may be well, however, to briefly describethe construction and operation thereof. It utilizes a valve piston 52slidably mounted in the upper end of the cylinder 17 above anintermediate cylinder head 53, indicatedin dotted lines in Figure 4.When the piston 21 is in its normal lowered or retracted position, highpressure air enters the upper end of cylinder 17 above valve piston 52through duct 29 and thus drives valve piston 52 downwardly until itseats against the intermediate cylinder head 53. Check valve means isprovided in the valve piston 52 for permitting high pressure air to passthrough valve piston 52 into the lower portion of the cylinder, therebyto drive the piston 21 to its fully retracted position.

When the slide valve 25 is shifted to advance position by energizationof solenoid 23, high pressure air flows into cylinder 17 through port 28which drives piston 21 upwardly in the piston. Such action of piston 21compresses the air trapped in cylinder 17 between piston 21 and valvepiston 52, until the pressure of such air becomes sufiicient to unseatvalve piston 52 from the intermediate head 53, whereupon the trapped airis instantly released to the atmosphere through suitable ducts, notshown.

The novel apparatus herein disclosed has been found extremely practicaland efficient in actual operation. It is controlled by movement of thecans through the upright supporting frame or structure 8, as a result ofthe can bodies successively engaging the contact roller 37 of the lowercontrol switch 32. The knocker frame is also returned to its normalposition by air pressure as a result of the upper control switch 33being closed by upward movement of the knocker frame, thereby to directthe high pressure air to the opposite end of the piston to cause it toreturn to its normal lowered position. A suitable bumper element 53 maybe secured to the upper cross member 14 of the knocker frame to cushionits engagement with the upper cross bar 11 of the supporting frame.Similar cushion elements 54 are shown secured to brackets 55 forlimiting the downward movement of the knocker frame, as will beunderstood by reference to Figures 1 and 2.

The foregoing detailed description has been given for clearness ofunderstanding only, and no unnecessary limitations should be understoodtherefrom, but the appended claims should be construed as broadly aspermissible in view of the prior art.

I claim as my invention:

1. In an apparatus of the class described, conveyor 6 means fortransporting containers from one place to another, and each containerhaving a cover frictionally .secured thereto, a supporting structuremounted over the conveyor, knocker means movable in said supportingstructure and engageable with opposite sides of the can cover, and meanscontrolled by movement of the containers to automatically effectoperation of said knocker means to unseat each container cover, as thecontainers successively pass said knocker.

2. In an apparatus according to claim 1, wherein two control elementsare provided for controlling the operation of the knocker, one of saidcontrol elements being operable by traveling movement of the containerto initiate operation of the knocker, and the other of said controlelements being positioned to be engaged by the knocker to effect returnmovement of the knocker after unseating a cover.

3. In an apparatus of the class described, a conveyor for transportingfilled containers from one station to another, each of said containershaving a closure frictionally secured in the open top thereof, saidclosures having their perimeters extending slightly beyond the uppermarginal rims of their respective container tops, a supporting structuremounted over the conveyor, 21 knocker mounted for vertical slidingmovement in said supporting structure, means for actuating said knockerincluding a fluid-operated device having a connection with a source offluid under pressure, and a control element positioned to be engaged byeach container passing beneath said knocker, thereby to effect theadmission of pressure fluid to said device and cause it to operate theknocker and automatically unseat the closure from the container top.

4. In an apparatus according to claim 3, wherein the control means forsaid knocker includes a pair of vertically spaced control elements, onebeing positioned to be engaged by traveling movement of the container toinitiate operation of the knocker, and the other being engageable withthe knocker to effect the return movement thereof.

5. In an apparatus of the class described, a conveyor for transportingmilk cans from one station to another, the open top of each can having acylindrical neck and the can closure having a depending skirt fittinginto said neck and provided at its upper end with an umbrellalike topwall having its perimeter projecting slightly beyond the perimeter ofthe can top, a supporting structure over the conveyor having verticallydisposed guides therein, a knocker comprising a rectangular framemounted for sliding movement in said guides, said knocker frame beingprovided at its lower end with inturned terminals normally positionedbeneath the path of travel of the perimeters of the milk can closures, apneumatic cylinder fixedly mounted in the supporting structure andhaving a piston therein having one end connected to the knocker frame,means for conducting air under pressure to said cylinder to actuate thepiston and said knocker and cause the terminals of the knocker tosimultaneously impinge against the perimeter of a can closure with ahammerlike action, thereby to unseat the closure from the can top.

6. In an apparatus according to claim 5, wherein means is provided forreturning the knocker to its normal position by fluid pressure.

7. In an apparatus according to claim 6, wherein a solenoid-actuatedvalve is provided for controlling the supply of air under pressure toand from the cylinder, the operation of said valve being automaticallycontrolled by alternate actuation of vertically spaced switch elementshaving electrical connections with said solenoidactuated valve and witha source of electrical energy, one of said switch elements beingpositioned to be actuated by traveling movement of the milk cans toeffect operation of the knocker and cause it to engage and un seat theclosure of each can passing thereby, and the other of said switchelements being engageable with the knocker to efiect the return movementof said knocker.

8. In an apparatus of the class described, a conveyor for transportingmilk cans from one station to another, a supporting structure over theconveyor having vertically disposed guides therein, a knocker comprisinga rectangular frame mounted for sliding movement in said guides andcomprising top and side members, said side members being provided attheir lower ends with inturned terminals normally positioned beneath thepath of travel of the perimeters of the milk can closures when saidclosures are in normal closed positions, a pneumatic cylinder fixedlymounted in the supporting structure and having a piston projecting fromthe upper end thereof and secured to the top member of the knockerframe,

References Cited in the file of this patent UNITED STATES PATENTS1,922,772 Lathrop Aug. 15, 1933 2,184,117 Fechheimer Dec. 19, 19392,570,186 Almgren Oct. 9, 1951 2,612,065 Packer et al. Sept. 30, 1952 M1,4,, we,

